Microresonators are relatively small acoustic resonators that can be used to form frequency filters or oscillator references. Generally, microresonators are manufactured through employment of integrated circuit (IC) manufacturing techniques, such that multiple resonators with a wide range of resonant frequencies (32 kHz to 10 GHz) can be manufactured on a single substrate. Oftentimes, microresonators are employed in connection with radio frequency band or channel selection.
Relatively recently, microresonators have become of research interest due to their small size, high quality factor (Q), CAD defined low to moderate impedance, potential monolithic integration with radiofrequency (RF) circuitry, and ability to realize multiple frequency filters operating from 10 kHz to 10 GHz on a single chip. The realization of numerous (tens to hundreds) multiple frequency filters on a single substrate can reduce component count in wireless handsets and enable frequency bandwidth and waveform diverse cognitive radios.
While impedance and frequency of desired extensional modes in microresonators can be relatively accurately adjusted using known equations and reduced order finite element models to synthesize a variety of different filter architectures, spurious modes arising from multiple sources may degrade the ultimate filter performance.